 | The following is a feature request for Wikipedia, the details of which may still be in development or under discussion. As a whole, this request should be discussed with the developers, who will decide whether or not to act on it. |
Category intersection is the ability to find all articles that are members of more than one category. It requires a change to the MediaWiki software as well as a major change to the policies related to how categories are populated. It is hoped that these changes will solve some long-standing categorization problems and end some common conflicts between Wikipedia editors. Category intersection also offers the possibility of adding several new features that will benefit users by adding valuable research and indexing tools as well as making the category system easier to manage.
Many existing categories are logically the intersection of attributes for which "primary" categories exist, for example Category:American actors is logically the intersection of Category:Actors and Category:American people. Although these "primary" categories are today generally subdivided into subcategories, if they were directly (fully) populated the "intersection categories" could be automatically generated. Categories in the German Wikipedia are already organized into fully populated primary categories.
This proposal tries to envision the changes necessary to make category intersection a reality. It is designed to augment the current categorization system, not replace it.